title: Extended graphical model for analysis of dynamic contrast-enhanced MRI.
abstract: Kinetic analysis with mathematical models has become increasingly important to quantify physiological parameters in computed tomography (CT), positron emission tomography (PET), and dynamic contrast-enhanced MRI (DCE-MRI). The modified Kety/Tofts model and the graphical (Patlak) model have been widely applied to DCE-MRI results in disease processes such as cancer, inflammation, and ischemia. In this article, an intermediate model between the modified Kety/Tofts and Patlak models is derived from a mathematical expansion of the modified Kety/Tofts model. Simulations and an in vivo experiment involving DCE-MRI of carotid atherosclerosis were used to compare the new extended graphical model with the modified Kety/Tofts model and the Patlak model. In our simulated circumstances and the carotid artery application, we found that the extended graphical model exhibited lower noise sensitivity and provided more accurate estimates of the volume transfer constant (K(trans)) and fractional plasma volume (v(p)) than the modified Kety/Tofts model for DCE-MRI acquisitions of total duration less than 100-300 s, depending on kinetic parameters. In comparison with the Patlak model, we found that the extended graphical model exhibited 74.4-99.8% less bias in estimates of K(trans). Thus, the extended graphical model may allow kinetic modeling of DCE-MRI results with shortened data acquisition periods, without sacrificing accuracy in estimates of K(trans) and v(p).
authors.affiliation: Department of Radiology, University of Washington, Seattle, Washington 98109, USA.
authors.forename: Huijun
authors.initials: H
authors.lastname: Chen
authors.forename: Feiyu
authors.initials: F
authors.lastname: Li
authors.forename: Xihai
authors.initials: X
authors.lastname: Zhao
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
authors.forename: Brian
authors.initials: B
authors.lastname: Rutt
authors.forename: William S
authors.initials: WS
authors.lastname: Kerwin
mesh_terms: D000465:Algorithms; D002340:Carotid Artery Diseases / Q000175:diagnosis; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015233:Models, Statistical; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media